Abstract: Cashew plantations of Cuddalore district has been considered to be the key source of clonal gardens for VRI 3 cashew graft production in Tamil Nadu and Panruti cashews have unique demand in the world market for its nut quality. However, majority of cashew kernel and CNSL processing units in Cuddalore district relied by and large on imported raw nuts to continue their units in operation for at least 200 days a year. Thane cyclone (December, 2011) occurrence in the district has worsened the cashew grower’s situation affecting their livelihood and thereby cashew production in peril. Hence, the constraints of cashew production from establishment in Cuddalore district has been analysed and KVK’s intervention in providing technological solution to overcome the recent thane cyclone loss, despite natural reoccurence in cashew within 2-2.5 months for sustainable cashew production in the district. The essential technological package consist of replacing the old senile and thane cyclone damaged cashew plantations with VRI 3 grafts of 3 months to 1 year old, laser guided land leveler for leveling the undulated lands after tree clearing, use of post-hole diggers for planting new cashew grafts, adopting high density planting method in drip-fertigation system, practicing training and pruning techniques in determining the tree’s frame work, encouraging cultivation of intercrops for income generation during the juvenile period and plant protection aspects to be carried out in the new cashew plantations.

Cashews (Anacardium occidentale L.), are high value dry fruits and India is a major player on the cashew in the world. Although cashew cultivation originated in Brazil, at present cashew is being cultivated in Asia, Africa and Latin America. Cashew was first introduced into India by Portuguese missionaries during the 16th century in Goa and Malabar Coast, which later served as the main centers of dispersal to other parts of the country (De Costa, 1978). In India cashew is mainly grown along the west coast of Maharashtra, Goa, Karnataka and Kerala, whereas in Tamil Nadu, Andhra Pradesh, Orissa and West Bengal along the east coast. To a limited extent it is also grown in Manipur, Meghalaya, Tripura, Andaman and Nicobar Islands and Chattisgarh. The cashew industry in India is largely an export-oriented industry which employs great number of women to process the nuts. It was only from the early twentieth century that the commercial value of cashew kernel for export and foreign exchange earnings were realized. However, the Indian processing industry has long been dependent on imported cashew nuts. The degree of import dependency has been increasing over time, especially since the mid-1980s. This increasing dependency is attributed to the failure of domestic raw nut production to catch up with growing demand for cashew kernels from both within and outside the country. Presently we are importing raw cashew nuts from African countries, especially Mozambique and ever since most of the African countries started to establish their own raw cashew nut to kernel processing factories, India is facing problem in importing raw nuts as well.

Market for cashews is gradually increasing over the period, whereas its supply is limited. In India the large number of cashew processing units needs about 1.3-1.4 million tons of raw cashew nuts per annum (Bhatt et al., 2011). In order to meet the requirement of the processing industry, India imports about 0.60 -0.70 million tons of raw cashewnuts annually from African and other countries. As these countries have started to establish their own processing units, the availability of raw cashew nuts for import is reducing gradually. Hence, there is an urgent need to increase the production to meet the requirement of the processing factories.

CASHEW PRODUCTION AND PROCESSING IN CUDDALORE DISTRICT

The average share of cashew to total area was the highest in Tamil Nadu (77%) and better demand for raw cashew nut was the most important factor that favoured cashew cultivation in Tamil Nadu (Venkattakumar, 2009). Cuddalore district in Tamil Nadu state was considered to have the maximum area and production under cashew than other cashew production districts in the state. In early years, the cashew industry was mostly located in Kerala, which then had over 50% of cashew plantations in the country. But land ceiling legislation restricted the expansion of cashew sowing in Kerala, as demand for cashew nuts grew (Pavaskar and Kshirsagar, 2012). Cashew popularly known as the ‘Gold mine’ of wasteland was initially introduced into the Cuddalore district (then South Arcot) from konkan coast of Kerala in the early 19th century during British period mainly to meet out their demands of raw cashew nut, as the landscape favoured growth of cashew trees. Cashew is generally grown on neglected land, soils prone for high degree of erosion and usually no intensive soil disturbing activities are required for this crop (Bhat and Venkattakumar, 2006).

a. Milestones in Research and Extension

Originally traditional cashew verities from Kerala were introduced and only after establishment of Cashew Research Station, Vriddhachalam in 1963, exclusive researches on cashew varietal development began in this district. Research efforts resulted in development of 4 improved cashew varieties viz., VRI-1 (1981), VRI-2 (1985), VRI-3(1991) and VRI- 4 (2000) and one hybrid, VRI (CW) H1(2009). Among the improved varieties released from RRS, Vriddhachalam variety VRI-2 (1981) was considered to be the National Variety, as it is suitable to be grown in all cashew growing tracts of India.

Softwood grafting technique had been standardized in the early 1980’s both at NRC Cashew and AICRP on Cashew. This technique has been commercialized for large scale production of cashew grafts. During 1982 the Cashew Research station, Vriddhachalam was upgraded as Regional Research Station under NARP for North Eastern Zone.

Krishi Vigyan Kendra, Vriddhachalam was established in 1985 and it started creating awareness among the cashew growers regarding the benefits of planting grafts of improved varieties than seedling progenies through OFT, FLD, on and off campus trainings. The Kendra concentrated on imparting skill based trainings on the production of cashew grafts in the poly greenhouse nursery from 2004 onwards for duration of one week to four weeks per training. It even, played a major role developing the trainees into successful entrepreneurs, as a result of which around 30 cashew graft production nurseries sprouted to grow in the district. In addition to this, KVK is involved in training the farmers on vermicompost production from cashew farm wastes.

Cashew Grafts Production is mainly concentrated in Regional Research Station, Krishi Vigyan Kendra and two State Horticulture Farm (Vriddhaclam and Neyveli) of this district to meet out the requirements of the southern Districts of Tamil Nadu viz., Kanyakumari, Tuticorin, Thirunelveli, Ramnad, Dindigul and other Districts besides the local demand of the Cuddalore district.

The importance of improved technologies in cashew was realized only with the introduction of “Model Clonal Cashew Garden” (MCCG) scheme, under which improved varieties are supplied to the farmers (Johnson and Manoharan, 2009). Tamil Nadu state development department’s viz., Horticulture, Agriculture and Rural Development, Tamil Nadu Forest Plantation Corporation Limited (TAFCORN) were involved in area expansion under improved cashew varieties and rejuvenation of senile cashew orchards under scheme’s such as Integrated Horticulture Development Scheme, National Horticulture Mission, Comprehensive Wasteland Development programme and Watershed Development programme.

b. Development of Cottage industry and Marketing of Cashew

India was the first country to hit the world market with cashew kernels and it was she who pioneered cashew processing as an industry. Even though not much is known of the origins of the industry, it has been recorded that cashew processing on a commercial scale was first started in the mid 1920's by Roch Victoria, a Sri Lankan who migrated to Kollam of Kerala. First export units were established by W.T. Anderson under the name Indian Nut Company in Kollam in India. Cashew nuts were fried in pans and kernels extracted, blanched, graded, and packed in wooden tea chests lined with newspaper before being shipped to the USA. Later, metal tin containers replaced tea chests followed by vacuumed Tin containers and since 1954 machines were used to infuse tin containers with carbon dioxide gas.

Cashew processing facilities vary largely in size. Basically, they can be divided into three categories: cottage processors, semi-industrial processors, and industrial processors. Cottage Industry in the field of cashew has grown up in an increasing manner in the last five years in Cuddalore district. In the district, there are around 250-300 household cashew processing units, 25-30 medium sized export oriented units and 5 major large scale export oriented units by 2012. Even though machines were in use for roasting, shelling and CNSL extraction since 1960’s, the process of shelling, removal of testa and kernel grading by size are still being carried out by manual operations only. About 95 % of the employee’s in the cashew industry in this district are rural women.

Marketing of cashew nut is not properly organized. The channel consists of the producer, village merchant, wholesalers or agents and exporters. Without value addition, the nuts are being sold as raw nuts to the local traders. Often there are intermediaries or wholesalers between the traders and manufactures has resulted in middleman playing an important role in marketing the nuts, thereby reducing the margin or dividends due to the cashew farmers (Johnson and Manoharan, 2009).

c. Cashew Export and Agri Export Zone

The Cashew Export Promotion Council of India (CEPC) was established by the Government of India in the year 1955, with the active cooperation of the cashew industry with the object of promoting exports of cashew kernels and cashew nut shell liquid from India. India has been exporting the cashew kernels since early part of 20th century. Export earnings have been on the increase since 1985. Between 1980 and 1985, although export earnings increased, quantity of cashew kernels exported decreased. Since 1985, there is a steady growth in the quantity of cashew kernels export market.

Memorandum of Understanding (MOU) was signed between Tamil Nadu Government and Government of India in 2005 to set up the Agri Export Zone for Cashew at Panruti , first of its in India for Cashew by the ministry of commerce. It is a joint Venture beween Tamil Nadu Industrial Development Corporation Ltd (TIDCO) and the Chennai-based M/s. Sattva group of companies with 26% equity participation. The project covered five districts in and around Panruti viz., Cuddalore, Thanjavur, Pudukkotai, Perambalur and Sivaganga accounting for nearly 82% of the total cashew production in the state with 45,000 tonne capacity spread across 85,000 acres of land and 36 farmers as Shareholder.

Any cashew project development in that area can get assistance from APEDA (Agricultural and Processed Food Products Export Development Authority) besides assistance from ASIDE (Assistance to States for Development of Export Infrastructure and other activities) for development of infrastructure facilities. A common state-of-the-art processing and packaging unit in Panruti spread across about two acres through the special purpose vehicle (SPV) has been developed in the cashew AEZ to promote cashew exports. Cashew kernels processed from this AEZ were exported to the countries like USA, Dubai, Saudi Arabia, Syria and Singapore as deemed export sales.

d. Cashew in Thane cyclone Disaster

Total area under cashew was estimated to be 33,000 ha, out of which 32,162 ha were reported to be damaged by 2011 thane cyclone in the district. Out of this 65 % of the cashew trees were of traditional varieties and around 35 % were of noted VRI series varieties. Among the VRI series cashew varieties, area covered under VRI-2 were 3 % and VRI-3 were of 32 %. The instantaneous traumatic effect of Thane cyclone took a heavy toll on the lives and livelihoods of cashew growers and cashew, the prime export crop of Cuddalore district. In due course of 2-2.5 months after thane cyclone incidence, natural rejuvenation occurred in cyclone damaged cashew plantations proving its semi hardiness nature. In this regard, a revised damaged cashew tree assessment was carried out, which suggested that about 8,700 ha need to be replanted with cashew grafts. A Hi- tech model demonstration cashew field has established at Mel Irrupu village of Panruti under National Horticulture Mission.

TECHNOLOGICAL INTERVENTIONS

In India, the productivity of cashew nut is the highest in Maharashtra due to the fact that cashew plantations established were with grafts of high yielding varieties followed by Kerala, where their soils are very fertile. Hence, cashew production and productivity could be enhanced by implementing good management practices and by planting the grafts of high yielding variety. The following proven technologies were considered essential for adoption in order to sustain cashew production in Cuddalore district.

a. LASER GUIDED LAND LEVELER

The non-uniformity of application depth markedly affects efficiency of utilization of irrigation water. In the face of increasing resource constraints (land, labour, and water), new resource conserving technologies must be developed and adopted in both irrigated, and rainfed ecosystems (Jat et al., 2006). The advanced method to level or grade the field is to use laser-guided leveling equipment. The introduction of laser leveling in the 1970’s produced a silent revolution that has raised potential of surface irrigation efficiency to the levels of sprinkler and drip irrigation (Erie and Dedrick, 1979). Laser land leveling technique is well known for achieving higher level of accuracy in land leveling. Laser leveling is a process of smoothening the land surface (± 2 cm) from its average elevation using laser equipped drag buckets to achieve precision in land leveling.

Laser leveler requires 45 HP or more HP tractors. The laser controlled system consists of a laser transmitter, laser receiver, survey receiver, an electrical panel and a twin hydraulic control valve. These levelers are implements consisting of a blade acting as a small bucket for shifting the soil from higher to the low-lying positions (Fig 2). Laser-guided land leveling allows reducing considerable amounts of water use because of a more uniform water distribution over the field (Abdullayev et al., 2007). This is due to the effective smoothening of the soil surface, which in turn reduces not only the irrigation duration ,amounts of water applied to a field but also in improving the use efficiency of precious inputs.

b. TRACTOR MOUNTED POST HOLE DIGGER (AUGER)

A study revealed that an increase of 0.2 to 1.3 g in individual nut weight was due to the effect of in-situ soil and water conservation measures (Manivannan et al., 2010). In this regard, digging of pits of 60 cm3 size and the depth of the pit can be increased upto 3 feet, to which 25 kg of farmyard manure or vermicompost to the top soil along with 1 kg of neem cake, before planting is considered beneficial in soil moisture conservation. In addition, digging pits of 60 cm3 size manually would be a cumbersome operation to plant new grafts in a large area. When the pits are dug manually among the prevailing agriculture labour shortage, the pits would be shallow, resulting in formation of shallow root system. Hence, it was decided that, the tractor mounted post-hole digger would be very useful in formation of pits of desired dimension through drilling mechanism under the circumstances of labour shortage. The tractor mounted post-hole digger also finishes the task in a shorter span of time (40 – 60 sec /pit) and the area coverage is also higher when compared to human efforts.

c. PLANTING OF VRI-3 CASHEW GRAFTS

Cashew being a cross pollinated crop, its progenies raised through seeds cannot be expected to perform true to type and thus heterozygous in nature (Aiyadurai and Koyamu, 1957). Most of the cashew plantations in the country have been raised from open pollinated seeds of unknown pedigree. Hence, if high yields of superior quality are desired, then the best clones must be selected and propagated vegetatively (Swamy, 1997).

Cashew seedling progeny selected from Edianchavadi village of South Arcot district was released in 1999 as variety VRI-3 by Regional Research Station, Vriddhachalam. The prominent nut character of this variety is that it is easy to peel the testa off the kernel and since the nuts were bold in size, they are suitable for export quality. VRI -3 performances well under irrigated conditions and are highly suitable for Tamil Nadu.

The major reason for the reluctance of farmers to take up cashew cultivation is the long gestation period of 10-11 years in obtaining stabilised yields, when the orchard was established with seedling progenies. While the graft planted cashew starts yielding from third year onwards with stabilised yield realized from 8 years after planting.

KVK alone has planned to produce 50, 000 VRI-3 cashew grafts to cater the needs of the farmers. Generally, cashew grafts of three months old would be given to farmers for planting. But in order to increase the survival rates of the grafts in the new plantations, it is also planned that 1 year old cashew grafts produced in polybags would be distributed to the farmer’s for better establishment in the field. In general VRI-3 cashew graft production of the district for the current year is estimated to be 25 lakhs.

d. HIGH DENSIY PLANTING SYSTEM

Canopy expansion rate of cashew is very slow during early years of growth and development. Cashew utilizes hardly 1.5 per cent of the land area during the first year. VRI-3 is most desirable for high density planting, as it has compact canopy. Proper training should be done in the initial years to achieve semi globular canopy with uniform spread. The success of High Density Planting (HDP) depends upon the initial plant population and the time of thinning at later stages.

High density planting reduces weed growth due to early ground coverage by the crop canopy and also reduction in soil temperature thereby increase in soil moisture content especially during peak summer season and also through mulching effect. Regular pruning is needed to contain the canopy. In later years for instance, 11th year after planting, it is necessary to thin out the tree population to 50 per cent by removing every alternate tree in each row. Cashew yield per unitt area can be increased by 2 to 3 folds in high density planting (500 plants per hectare) as compared to the normal density planting (200 plants per hectare). In the Cuddalore district, of the revised thane cyclone affected area of 8,700 ha after natural rejuvenation, it was decided to cover 1200 ha under high density planting system (5 m X 4 m spacing) and remaining 7,500 ha under normal spacing (7 m X 7 m) planting system.

e. DRIP-FERTIGAION SYSTEM

In cashew, majority of the feeder roots are found on the surface layer of the soil, as they’re shallow in nature. About 89 per cent and 54 per cent of feeder roots occur within 2 m radius and 0-1 m depth respectively. Irrigating 80 litres/tree once in four days intervals through drippers from December to March (Total irrigation of 2400 litres / tree/ season) can also increase yield substantially. In well grown trees, roots can extend to 1½ to 4 times beyong its canopy, resulting in root inter-locking and thereof competition for available resources. However, when cashew grafts in High density planting system are planted with drip-fertigation system from the time of planting, its root architecture can be confined within its canopy perimeter and especially the feeder roots, being at the spot of the dripper’s delivery end.

225:75:75 NPK/ha can be applied through fertigation from December to March at one week intervals. With use of water soluble fertilizers, quantity of fertilizers to be applied can be reduced to 75 per cent the quantity of the recommended dose. Yield can be increased from 1 ton per ha in case of high density planting without irrigation to 2 tons per ha with fertigation. It is desirable to have more than 1.0 organic carbon content in the soil. It has also been found that farm yard manure or compost of 30 to 35 kg/adult tree or 20 of poultry manure per adult tree gave better results. Green manuring crops like sun hemp can be grown during rainy season to improve the soil fertility.

f. INTERCROPPING SYSTEM

Intercropping has reduced weeding period of cashew by about 50 per cent when compared to sole cashew crop (Adeyemi, 1989). Growing of intercrops such as black gram (Vamban-6, Co-6)), groundnut (VRI-2, VRI-6, TMV-13), sesame (VRI-1, VRI-2) and cowpea (Co-6, Co-7) in cashew plantations up to 3 years for maximum utilization of the interspace during rainy season is beneficial. In Cuddalore district, apart from the mentioned intercrops, on KVK’s recommendation cashew growers have grown brinjal (PLR-2), annual moringa ( PKM-1), fodder crops and Redgram (Co(RG)-7). Even mixture of these intercrops like annual moringa at 1m distance from the young cashew grafts (5 X 4 m) , the space in between, groundnuts were sown and on the borders redgram were planted in the farmer’s field of Mr. G.Venkatesan and Mr.V.Shankar from Chinnakandayan Kuppam village of this district.

g. CANOPY MANAGEMENT TECHNIQUES

In High density system of planning, canopy development within manageable size is most essential. Canopy management like training and pruning, affects the quantity of sunlight intercepted by the trees, as tree shape determines the presentation of leaf area to in coming radiation (Singh, 2010). Cashew, a fast growing woody perennial is characterized by spreading branches and irregular tree shape. Such trees are difficult to manage and result in poor nut yield in later years.

Plants should be meticulously trained from the first year of planting itself so as to derive maximum benefit of high density system of planting and avoid thinning of plants. In modified Leader System, the sprouts on leaf axils of the young grafts were removed periodically during the first year as and when required. A clear stem of 0.5-.75m from the ground level should be maintained and later the trunk is allowed to branch in all directions. The central leader should be detopped at a height of 2.5-3 m and a clear semi globular canopy should be allowed to form. The canopy requires annual maintenance by minimum trimming, thereby helps in reduced dead wood and water shoot development. Hence, tapping maximum sunlight can be achieved.

h. PLANT PROTECTION

h.1. Cashew Stems and Root Borer

The Cashew stems and root borer (CSRB) Plocaederus ferrugineus L. is one of the serious pests in cashew. The tiny grub of CSRB bores into the fresh tissue and feeds on the phloem and xylem tissues of the trunk and root with making irregular tunnels. Due to extensive tunneling the vascular tissues were damaged and plant sap movements were arrested and ultimately trees die (Sahu and Sharma, 2008).

Prophylactic measures like maintaining sanitation of the new plantation, training the newly planted grafts to induce branching at one meter height from the ground level, painting the base of the tree trunk up to the height of three feet from the ground level with coal tar: kerosene in 1: 2 ratio or swabbing neem oil (5 %) coupled with soil application of Sevidol 4G @ 75 g per tee to prevent egg laying adult beetles. Preventing planting of CSRB host trees like Silk cotton and Moringa inside or in the vicinity of the new cashew plantations.

h.1.2. Tea Mosquito Bug

Among the several pests infesting cashew, Tea mosquito bug (TMB), Helopeltis antonii Signorent is the most destructive pest of cashew causing damage to tender shoots, inflorescence, immature nuts and apple of various stages of crop development. The nymphs and adults suck the sap from tender shoots, inflorescence, immature nuts and apple. In very severe case of damage even up to 100% loss in the yield may be observed. To control this pest many insecticides are recommended at present (Jalgaonkar et al., 2009).

TMB incidence appears to coincide with flushing period and persists in the field through flowering and fruiting periods. The plant protection measures are to be warranted at these 3 critical periods of crop development to avoid nut yield loss due to TMB incidence. As prophylactic measures, spraying of prophenosphos 35 EC (1ml/l) and carbendazeim (1g/l) during the flushing period and if incidence still persist, another spray of chloropyriphos (2.5ml/l) at one week interval is recommended (SWC, TNAU, 2011).

h.1.3. Die Back or Pink Disease

Die Back or Pinkdisease is caused by Corticium salmonicolor, in which the affected branches initially show white patches on the bark and a film of silky thread mycelium develops on the branches during the monsoon season and later on the fungus develop pinkish growth on upper surface of the bark. In due course of time, the bark splits and peels off and the affected shoots starts drying up from the tip. The disease can be controlled by the pruning the affected branches below the spot of infection and destroying them; protecting the cut surface by application of Bordeaux paste and spraying of Bordeaux mixture 1% twice in May to June before the onset of monsoon.

CONCLUSION

Cashew nuts,with its unique combinations of fats, carbohydrates, proteins and variety of minerals and vitamins, proved to be a nut of demand in the world market. Presently, India is the second largest producer of cashew nuts in the world and most of her productions were processed for export. Cashew since its introduction has adapted well to the climatic conditions prevailing in Cuddalore district and by adopting proven management technologies along with planting of grafts of high yielding varieties, the production and productivity of cashew can be enhanced, thereby boosting the cottage and export oriented units through AEZ in Panruti with the scope of attaining self-sufficiency in the near future.

ACKNOWLEDGEMENT

Author Dr.S.Haripriya would like to extend her gratitude to scientist’s Dr.S.Jeeva, Dr.V.Ambedgar, Dr.M.S.Aneesa Rani of Regional Research Station, Vriddhachalam; Mrs.P. Manimozhi, AssistantDirector of Horticulture, Vriddhachalam and Mr.Ramalingam, Deputy Director of Horticulture (Planting Materials), Cuddalore; Cashew growers and Cashew Export units of Panruti for their kind cooperation in providing needed information.

REFERENCES

Abdullayev, I., Ul Hassan, M. and Jumaboev, K. 2007. Water Saving and Economic Impacts of Land Leveling: The Case Study of Cotton Production in Tajikistan. Irrig. Drain. Syst. 21: 251-263.